Is Unix stdio slow?
Brandon S. Allbery
allbery at ncoast.UUCP
Tue Oct 18 07:34:05 AEST 1988
As quoted from <104 at minya.UUCP> by jc at minya.UUCP (John Chambers):
+---------------
| > I will go as far as to say that standard output to pipes should be
| > line buffered, since we no longer put pipes in files.
|
| BTW, on every Unix system I've ever used, a pipe is a file. What could
| the stuff after the comma in the above quote possibly mean? Is there a
| new implementation of pipes that doesn't use file descriptors? I sure
| hope not; that sure would be a giant step backwards.
+---------------
He means that on V7-based systems (including SVR3), pipes are essentially
implemented in the kernel in a way that's almost identical to:
p[1] = creat(some_temp_file, 0);
p[1] = open(some_temp_file, 0);
unlink(some_temp_file);
whereas under BSD pipes are linked socketpairs and under SVR4 they're
supposed to be a variant of the "clone" device (essentially, the STREAMS
version of sockets) and are implemented quite differently.
++Brandon
--
Brandon S. Allbery, comp.sources.misc moderator and one admin of ncoast PA UN*X
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